Light emitting diodes, LEDs, are employed in a wide range of lighting applications. As LEDs have the advantage of providing a bright light, being reasonably inexpensive and has low power consumption, it is becoming increasingly attractive to use LEDs as an alternative to traditional lighting. Furthermore, LEDs have a long operational lifetime. As an example, LED lamps may last 50 000 hours which is up to 50 times the operational life of an incandescent lamp.
To achieve such a long operational lifetime, one important aspect to consider is the heat management of the LEDs so in order to avoid overheating of the LEDs or the LED module. This is not an uncomplicated task since LEDs release heat backwards, i.e. in the opposite direction compared to the direction of the light beams, in comparison to traditional lighting which mainly transfer the generated heat by the radiation of the light. Especially, when LEDs are mounted in, for example, roofs or ceilings it may become complicated to provide sufficient cooling due to the reduced surrounding space of the LEDs. Moreover, when for example using LEDs for indoor applications, such as accent and down lighting applications, there is a need for compact and high lumen packages which allows the projection of tight light beam angles. In such cases, a plurality of LEDs are placed together in a small area which provides such an amount of heat that a standalone heat sink may not be able to provide sufficient cooling.
A solution to this problem is to provide an active cooling element, such as e.g. fans or membranes, in order to provide a sufficient amount of cooling. However, these types of solutions are expensive and sometimes unreliable due to their limited operational lifetime. There is hence a further need of improvement in regards to heat management for LEDs.